134 CLASS IY. 
Yet, without microscopic investigation, even the colour of the 
organs of propagation is sufficient to point out the difference of the 
sexes; the testes are distinguished by a milk-white, the ovaria by 
a yellowish-brown or red colour. In ninety-eight specimens of 
fichinus Prrers found that forty-three were males and fifty-five 
females, so that the two sexes are nearly equal in numbers. In 
Comatula also, MUELLER found the sexes distinct; the ovaria and 
testes are here situated on the pinnule}. In Ophiura, on the other 
hand, they lie in the disc, round the stomach as ten structures 
composed of lobes and blind pouches, that run into a pedicle; in 
the spaces between every two rays two such structures are placed 
close together so as to form five pairs*. In the Star-fishes they lie 
in the angles between the rays, and have the form of bunches of 
beaded strings: in some species they extend into the rays; their 
number is double that of the rays. On the dorsal surface, in some 
specres, in each inter-radial space, two spots are found, which are 
perforated, sieve-like, by numerous closely arranged pores; these 
openings allow the ova or the seed to escape. In other species the 
products of the genital organs, which have been poured into the 
cavity of the body are probably allowed to pass out by the respira- 
tory tubules on the back. In the Sea-urchins five ovaries or testes 
lie on the inner surface of the shell, and fill the spaces between the 
ambulacral plates. They are of an oblong flattened form, and con- 
sist of numerous cecal pouches, which open into an excretory duct 
running through the midst of the organ. The duct then runs freely 
like a footstalk, by which the testis or the ovary is attached to the 
upper surface of the shell where it opens. There are thus five such 
openings, in five pentagonal calcareous plates around the anus. In 
Holothuric the ovary or testis is a bundle of branched tubes; these 
hang by their blind extremities downwards, and open above into 
a single excretory duct, being fastened to it like a brush. The 
oviduct or the efferent vessel lies along the anterior portion of the 
intestinal canal, and terminates near the anterior extremity of the 
body by a distinct opening on the dorsal surface. Near this canal 
1 They are figured in the Abh. der Berl. Akad. Bau des Pentacrinus, Taf. v. 
fig. 17, 18. 
2H. Ratuxe Beitriige zur vergl. Anat. u. Physiol., Reisenbemerkungen aus 
Skandinavien, Danzig, 1842, 4to, s. 116, 117. Tab, 1. fig. 3—7. 
